一、概述
本次是以java语言开发为例，计算出年月日对应的天干地支。
二、代码
1 public class MyDate { 2/** 3* 对于年月日的天干地支 4*/ 5private int year_ganZhi; 6private int month_ganZhi; 7private int day_ganZhi; 8/** 9* 关于阴历的相关信息 10*/ 11private static int[] lunar_info = {0x04bd8, 0x04ae0, 0x0a570, 0x054d5, 12 0x0d260, 0x0d950, 0x16554, 0x056a0, 0x09ad0, 0x055d2, 0x04ae0, 13 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540, 0x0d6a0, 0x0ada2, 14 0x095b0, 0x14977, 0x04970, 0x0a4b0, 0x0b4b5, 0x06a50, 0x06d40, 15 0x1ab54, 0x02b60, 0x09570, 0x052f2, 0x04970, 0x06566, 0x0d4a0, 16 0x0ea50, 0x06e95, 0x05ad0, 0x02b60, 0x186e3, 0x092e0, 0x1c8d7, 17 0x0c950, 0x0d4a0, 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4, 0x025d0, 18 0x092d0, 0x0d2b2, 0x0a950, 0x0b557, 0x06ca0, 0x0b550, 0x15355, 19 0x04da0, 0x0a5d0, 0x14573, 0x052d0, 0x0a9a8, 0x0e950, 0x06aa0, 20 0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260, 0x0f263, 21 0x0d950, 0x05b57, 0x056a0, 0x096d0, 0x04dd5, 0x04ad0, 0x0a4d0, 22 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b5a0, 0x195a6, 0x095b0, 23 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40, 0x0af46, 24 0x0ab60, 0x09570, 0x04af5, 0x04970, 0x064b0, 0x074a3, 0x0ea50, 25 0x06b58, 0x055c0, 0x0ab60, 0x096d5, 0x092e0, 0x0c960, 0x0d954, 26 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0, 0x092d0, 27 0x0cab5, 0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9, 0x04ba0, 28 0x0a5b0, 0x15176, 0x052b0, 0x0a930, 0x07954, 0x06aa0, 0x0ad50, 29 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65, 0x0d530, 30 0x05aa0, 0x076a3, 0x096d0, 0x04bd7, 0x04ad0, 0x0a4d0, 0x1d0b6, 31 0x0d250, 0x0d520, 0x0dd45, 0x0b5a0, 0x056d0, 0x055b2, 0x049b0, 32 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0}; 33/** 34* 记录天干的信息 35*/ 36private String[] gan_info = {"甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", 37 "壬", "癸"}; 38private String[] zhi_info = {"子", "丑", "寅", "卯", "辰", "巳", "午", "未", 39 "申", "酉", "戌", "亥"}; 40/** 41* 单例模式 42*/ 43private static volatile MyDate instance = null; 44private MyDate() { 45} 46 47public static MyDate getInstance() { 48 if (instance == null) { 49 synchronized (MyDate.class) { 50 if (instance == null) { 51 instance = new MyDate(); 52 } 53 } 54 } 55 return instance; 56} 57 58/** 59* 获取农历某年的总天数 60* 61* @param year 62* @return 63*/ 64private int daysOfYear(int year) { 65 int sum = 348; 66 for (int i = 0x8000; i > 0x8; i >>= 1) { 67 sum += (lunar_info[year - 1900] & i) == 0 ? 0 : 1; 68 } 69 //获取闰月的天数 70 int daysOfLeapMonth; 71 if ((lunar_info[year - 1900] & 0xf) != 0) { 72 daysOfLeapMonth = (lunar_info[year - 1900] & 0x10000) == 0 ? 29 : 30; 73 } else { 74 daysOfLeapMonth = 0; 75 } 76 return sum + daysOfLeapMonth; 77} 78 79/** 80* 初始化年月日对应的天干地支 81* @param year 82* @param month 83* @param day 84*/ 85public void initGanZhi(int year, int month, int day) { 86 //获取现在的时间 87 Calendar calendar_now = Calendar.getInstance(); 88 calendar_now.set(year, month - 1, day); 89 long date_now = calendar_now.getTime().getTime(); 90 //获取1900-01-31的时间 91 Calendar calendar_ago = Calendar.getInstance(); 92 calendar_ago.set(1900, 0 ,31); 93 long date_ago = calendar_ago.getTime().getTime(); 94 //86400000 = 24 * 60 * 60 * 1000 95 long days_distance = (date_now - date_ago) / 86400000L; 96 float remainder = (date_now - date_ago) % 86400000L; 97 //余数大于0算一天 98 if (remainder > 0) { 99 days_distance += 1;100 }101 //都是从甲子开始算起以1900-01-31为起点102 //1899-12-21是农历1899年腊月甲子日 40：相差1900-01-31有40天103 day_ganZhi = (int)days_distance + 40;104 //1898-10-01是农历甲子月 14：相差1900-01-31有14个月105 month_ganZhi = 14;106 int daysOfYear = 0;107 int i;108 for (i = 1900; i < 2050 && days_distance > 0; i++) {109 daysOfYear = daysOfYear(i);110 days_distance -= daysOfYear;111 month_ganZhi += 12;112 }113 if (days_distance < 0) {114 days_distance += daysOfYear;115 i--;116 month_ganZhi -= 12;117 }118 //农历年份119 int myYear = i;120 //1864年是甲子年121 year_ganZhi = myYear - 1864;122 //哪个月是闰月123 int leap = lunar_info[myYear - 1900] & 0xf;124 boolean isLeap = false;125 int daysOfLeapMonth = 0;126 for (i = 1; i < 13 && days_distance > 0; i++) {127 //闰月128 if (leap > 0 && i == (leap + 1) && !isLeap) {129 isLeap = true;130 if ((lunar_info[myYear - 1900] & 0xf) != 0) {131 daysOfLeapMonth = (lunar_info[myYear - 1900] & 0x10000) == 0 ? 29 : 30;132 } else {133 daysOfLeapMonth = 0;134 }135 --i;136 } else {137 daysOfLeapMonth = (lunar_info[myYear - 1900] & (0x10000 >> i)) == 0 ? 29 : 30;138 }139 //设置非闰月140 if (isLeap && i == (leap + 1)) {141 isLeap = false;142 }143 days_distance -= daysOfLeapMonth;144 if (!isLeap) {145 month_ganZhi++;146 }147 }148 if (days_distance == 0 && leap > 0 && i == leap + 1 && !isLeap) {149 --month_ganZhi;150 }151 if (days_distance < 0) {152 --month_ganZhi;153 }154}155 156/**157* 将年月日转化为天干地支的显示方法158* @param index159* @return160*/161private String ganZhi(int index) {162 return gan_info[index % 10] + zhi_info[index % 12];163}164 165/**166* 获取天干地支167* @return168*/169public String getGanZhi() {170 return "农历" + ganZhi(year_ganZhi) + "年 " + ganZhi(month_ganZhi) + "月 " + ganZhi(day_ganZhi) + "日";171}172 }
三、基本概念
天干地支，源自于中国远古时代对天象的观测。十干日：阏逢、旃蒙、柔兆、强圉、著雍、屠维、上章、重光、玄黓、昭阳。十二支日：困顿、赤奋若、摄提格、单阏、执徐、大荒落、敦牂、协洽、涒滩、作噩、阉茂、大渊献。
简化后的天干地支：“甲、乙、丙、丁、戊、己、庚、辛、壬、癸”称为十天干，“子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥”称为十二地支。
